【摘要】 研究了不同氮肥管理模式下的稻田氮素平衡特征和环境效应.在太湖主要入湖河流直湖港下游开展了农户常规施肥处理、缓控释肥处理、有机无机肥配施处理、按需施肥处理以及化肥减量优化处理5种氮肥管理模式的田间小区试验,实测了稻季的径流和淋洗氮损失,估算了氨挥发和N2O等气体损失,分析了不同氮肥处理下的环境排放量和氮素平衡特征.与农户常规施肥处理相比,其他处理在减少氮肥总投入量20%～40%的情况下产量与农户对照基本持平,氮肥利用率提高了14.5%～44%.不同氮肥管理模式下,缓控释肥处理和按需施肥处理的氮环境排放量最低,比农户施肥处理分别降低了52.8%和45.4%.在等氮量投入下,有机无机配施处理比纯化肥处理减少了环境氮排放量.农户施肥处理存在着明显的氮盈余,增加了麦季氮流失的风险,按需施肥处理略微出现氮亏缺,在一定程度上减少了麦季氮流失风险.新型缓控释肥处理和按需施肥处理能在不降低产量和效益的情况下,提高氮肥利用率,减少环境排放量,是值得在太湖流域推广的经济环保氮肥管理模式.更多还原

【Abstract】 Effects of nitrogen(N) management methods of paddy field on N export to environment and paddy N balance in Taihu lake region,China were studied.Field experiment including site-specific nitrogen management(SSNM),organic & chemical N fertilizer treatment(OCN),control released urea treatment(CRN),reduced chemical N treatment(RN) and farmer’s N treatment(FN) were conducted at the taihu lake region in 2008.N loss including runoff,leaching,ammonia volatilization and N2 O were calculated,and the N balance was evaluated.Results showed the grain yield of SSNM,OCN,CRN and RN treatments was identical with FN treatment,while the total N rate reduced about 20%-40%,and N use efficiency(NUE) increased 14.5%-44%.N export of SSNM and CRN treatments decreased 52.8% and 45.4% in comparison with FN treatment.Under the same N input,N export of OCN treatment was lower than pure chemical N treatment(RN).N surplus was observed in FN treatment,while N deficit existed in SSNM treatments.CRN and SSNM treatments could increase NUE,reduce N export without sacrifice of yield and benefit,and could be as an economic and environment-friendly measure to intensify in Taihu lake region.更多还原